Yeah get a digi with probe (you really only need warm side surface temp) from Walmart for $12, then stick the probe on the warm side of the tub over the center if your Uth or w/e you use!!!
0.3 Normals (Coilette, Athena and Mary Jane)
1.0 Pastel (De Sol)
1.0 Spider (Zeus)
1.0 Mojave (Prometheus)
0.1 Brazilian Rainbow Boa (Stella)
0.1 BCI (Kiyoko)